Hydrogen storage in pillared Li-dispersed boron carbide nanotubes

Ab initio density-functional theory study suggests that pillared Li-dispersed boron carbide nanotubes is capable of storing hydrogen with a mass density higher than 6.0 weight% and a volumetric density higher than 45 g/L. The boron substitution in carbon nanotube greatly enhances the binding energy of Li atom to the nanotube, and this binding energy (~ 2.7 eV) is greater than the cohesive energy of lithium metal (~1.7 eV), preventing lithium from aggregation (or segregation) at high lithium doping concentration. The adsorption energy of hydrogen on the Li-dispersed boron carbide nanotube is in the range of 10 ~24 kJ/mol, suitable for reversible H2 adsorption/desorption at room temperature and near ambient pressure.Comment: 17 pages, 4 figure

Research on Establishing the Indexes System of Controlling the Coal and Gas Outburst Accident

AbstractCoal and gas outburst accident aggravates with the increasing depth of coal mining, which amplifies geostress on coal seam, gas pressure and gas capacity. Studying on coal and gas outburst accident, this paper sets up the indexes system of controlling on the coal and gas outburst accident with consideration on technology factor, including basic technological work, reliability of relative system, prevention technology and concept, technological innovation, technic equipments, and management factor, including investment, management, institution configuration on governing gas, as two main elements

Passage to Rights: Rethinking Indigenous People’s Drinking Practices in Taiwan

This thesis aims to explicate the meaning of indigenous people’s drinking practices and their relation to indigenous people’s contemporary living situations in settler-colonial Taiwan. ‘Problematic’ alcohol use has been co-opted into the diagnostic categories of mental disorders; meanwhile, the perception that indigenous people have a high prevalence of drinking nowadays means that government agencies continue to make efforts to reduce such ‘problems’. Indigenous people in Taiwan still face continuous marginalisation and systemic discrimination which render drinking a prominent issue. However, interventions based on public health narratives lack efficacy due to discordant understandings of illness, moral experience and perceptions of culture. Based on 12 months of multi-sited research in Taiwan, my study finds indigenous drinking cultures have been both generated and reshaped by their life situations, both historically and contemporarily. Drinking practices today reveal suffering under structural violence but also show resistance emerging from social change. Drinking is also practised at the interstices of contested values that make health narratives invalid. An ever-reproducing drinking culture shows a gesture of self-fashioning under multiple sufferings, as well as strategies to restore livelihoods. In the time to pursue transitional justice, indigenous people’s symbolic sobriety unfolds through resistance against current governmentality over drinking in one sense, but fighting for autonomy in another. Therefore, drinking can be understood as a ‘passage to rites/rights’ that represents the struggle of indigenous people in search of traditional values and future respect

Cogging torque and torque ripple reduction of a novel exterior-rotor geared motor

The reduction of cogging torque and torque ripple in permanent-magnet motors to suppress the vibration and acoustic noise is a major concern for motor designers. This study presents a novel exterior-rotor geared motor which integrates a brushless permanent-magnet (BLPM) motor with an epicyclic-type gear reducer to form a compact structural assembly without extra transmitting elements. One of the special features of the geared motor lies in the gear-teeth of the epicyclic-type gear reducer merged with the stator of the BLPM motor. The gear-teeth serve as the interfacial medium to connect the BLPM motor with the epicyclic-type gear reducer, which provides functions not only for transmission to achieve a desired speed ratio, but also effectively reduce the cogging torque and torque ripple of the geared motor. Five shape models of pole shoes with different values of the shoe depth and the shoe ramp are presented to effectively reduce the cogging torque and the torque ripple. With the aid of the finite-element analysis, shape model III of the geared motor performs better than the existing BLPM motor on the cogging torque with 87 % decreasing and the torque ripple with 23 % decreasing. Such a unique characteristic of the geared motor is of benefit to the widely applications on accurate motion and position control systems

An Issue between Contemporary Theory and Modern Compositional Practice A Study of Joseph Straus's Laws of Atonal Voice Leading and Harmony using Webern's Opus 12/2 and Crawford's String Quartet Mvt. 3

In his recent research project, music theorist Joseph Straus extends the traditional notions of smooth voice leading and the quality of harmony in tonal music to describe atonal voice leading and harmony. To achieve this goal, Straus proposes a theory called fuzzy transformations to analyze atonal music. Based on his findings, he further concludes the law of atonal voice leading and that of atonal harmony, which state that compositions, especially those in "more conservative styles," do obey these two laws. To test the validity of Straus's laws, I use Crawford's String Quartet Mvt. 3 and Webern's song op. 12/2 as case studies, examining the potential strengths and inherent weaknesses in Straus's fuzzy transformations, and further pointing out a conflict between music theory and compositional practice